Major European airports are working to stabilize passenger processing after a cyberattack against Collins Aerospace’s MUSE check-in and boarding software triggered long queues, delays, and cancellations over the weekend. Heathrow, Brussels, and Berlin reported the heaviest disruption from late Friday, September 19, through Saturday, with recovery improving into Sunday but not yet complete.
Collins Aerospace, a subsidiary of RTX, described the issue as a “cyber-related disruption.”
Heathrow said most flights were operating by the morning of September 21, 2025, though manual workarounds and longer processing times persisted. Brussels Airport warned of continuing schedule impacts and advised passengers to arrive early, while Berlin Brandenburg reported ongoing constraints and continued to use contingency procedures at its terminals.
What we know about the attack
Initial airport statements and wire reports point to a targeted intrusion on the MUSE multi-user system that supports electronic check-in, bag tagging, and boarding. Airport operators stressed that the incident affected a vendor platform rather than airport safety systems or air traffic control.
Authorities in several countries have opened inquiries into attribution and system resilience. Collins and RTX have not publicly shared technical details beyond confirming the cyber incident.
By midday September 21, 2025, delay levels had eased at Heathrow, remained moderate at Berlin, and were heavier but improving at Brussels, according to airport updates and aggregated flight-status data referenced by wire services. Airlines continued to accommodate passengers whose check-in was handled manually during the outage.
The episode highlights the risk of concentration around shared passenger-processing platforms at large hubs. Even when flight safety is unaffected, the loss of automated check-in cascades into staffing surges at counters, gate holds, and knock-on delays across network banks.
